Undersea Cables: How Secure is the Internet’s Backbone from Cyber Attacks?

Finnish police seized a cargo ship last week suspected of damaging an undersea telecommunications cable in the Baltic Sea, an incident highlighting growing concerns about the vulnerability of critical infrastructure to sabotage. The vessel, the New New Polar Bear, was taken into custody following a joint investigation by Finnish authorities and the country’s border guard, according to a statement released February 27, 2026.

The incident comes amid heightened geopolitical tensions, particularly in the wake of Russia’s ongoing conflict in Ukraine, and increasing scrutiny of the security of undersea cables that carry the vast majority of global internet traffic. These cables, often laid across remote and poorly monitored ocean floors, are essential for international communications and financial transactions. Experts estimate that over 95% of international data travels via these submarine networks.

Although the Finnish investigation focuses on potential physical damage, the broader issue involves both physical threats and the potential for cyber attacks. Directly targeting the cables themselves is a complex undertaking. They are typically buried beneath the seabed near coastlines, and in deeper waters, accessing them requires specialized ships and equipment. Still, officials acknowledge the rising risk of deliberate disruption, as highlighted by a recent report from the International Cable Protection Committee (ICPC).

Despite the inherent difficulties, the potential consequences of a successful attack are significant. Disrupting these cables could cripple internet connectivity, disrupt financial markets, and impede communication between nations. Network redundancy – the existence of multiple cables connecting the same regions – is a key defense, allowing data to be rerouted if one cable is compromised. However, the rerouting process isn’t instantaneous and could still cause significant disruption.

Data traveling through these cables is also protected by encryption protocols, such as HTTPS and VPNs, making it difficult for attackers to intercept and decipher information even if they were able to access the physical cable. However, cybersecurity experts note that the vulnerabilities often lie not within the cables themselves, but in the systems and devices connected to them. Exploiting weaknesses in websites, networks, or user devices remains a more accessible avenue for malicious actors.

The Finnish investigation is ongoing, and authorities have not yet released details about the extent of the damage to the cable or the potential motives behind the alleged sabotage. The incident has prompted renewed calls for increased monitoring and protection of undersea infrastructure, as well as greater international cooperation to address the growing threat. The ICPC continues to work with governments and cable operators to promote best practices and enhance security measures.

As Russia faces accusations of hybrid warfare tactics against Western nations, the vulnerability of undersea cables has become a focal point of concern, as reported by CBS News. The incident in the Baltic Sea underscores the need for vigilance and proactive measures to safeguard this critical component of the global internet infrastructure.